Our estimates show a pandemic with an Rt values that has slightly increased from last week, while remaining below 1, most likely as a consequence of the half-term school holiday, following a sustained period of increasing infections that had converged to a plateau. As identified two weeks ago, the number of deaths has continued to increase, although increase continues only up until 9th November. This peak is at 167 deaths per day, which is much lower than the peaks of the first two waves of infection.
Plots of the IFR over time show that from the end of January we estimate a decreasing IFR in all adult age groups, but most steeply in the older ages. This drop indicates the benefits of immunisation against death over and above the benefits against infection. Following this drop, there has been a period of plateau followed by a gradual increase in the overall IFR to 0.26% (0.25%–0.26%). However, the age-specific IFRs appear to be falling, suggesting that the overall increase is due to shifting age patterns towards older people being infected. The estimated IFR is highest in the over-75s at 3.2% (3.1%–3.4%)
For context, in addition to the data used here, the number of reported new positive tests this week (by date of specimen) has been in decline since the national half-term holiday. As a caveat to this, trends in the number of reported cases are highly dependent on the volume and targeting of testing, the public’s testing behaviour and significant reporting delays, and therefore are difficult to interpret. This is exemplified by the fact that the proportion of tests that are positive (ratio between new positive cases and number of tests) is not falling similarly. Hospitalisations have stabilised and are no longer increasing, while the prevalence of infection, as estimated by the ONS Coronavirus Infection Survey, continues to follow the increasing trend shown over the last seven weeks reaching 2.0% in England: the highest level it has been in 2021 and close to the highest it has been during the lifetime of the survey.
Real-time tracking of an epidemic, as data accumulate over time, is an essential component of a public health response to a new outbreak. A team of statistical modellers at the MRC Biostatistics Unit (BSU), University of Cambridge, are working to provide regular now-casts and forecasts of COVID-19 infections and deaths. This information feeds directly to the SAGE sub-group, Scientific Pandemic Influenza sub-group on Modelling (SPI-M), and to regional Public Health England (PHE) teams.
We fit a transmission model (Birrell et al. 2020) to a number of data sources (see ‘Data Sources’), to reconstruct the number of new COVID-19 infections over time in different age groups and NHS regions, estimate a measure of ongoing transmission and predict the number of new COVID-19 deaths.
We use:
Data are stratified into eight age groups: <1, 1-4, 5-14, 15-24, 25-44, 45-64, 65-74, 75+, and the NHS England regions (North East and Yorkshire, North West, Midlands, East of England, London, South East, South West).
Value of \(R_t\), the average number of secondary infections due to a typical infection today.
The percentage of a given group that has been infected.
NB: negative growth rates are rates of decline. Values are daily changes.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | -0.01 | -0.02 | 0.00 |
| East of England | -0.02 | -0.04 | -0.01 |
| East Midlands | -0.03 | -0.04 | -0.01 |
| London | -0.01 | -0.02 | 0.01 |
| North East | -0.02 | -0.04 | 0.00 |
| North West | -0.03 | -0.05 | -0.01 |
| South East | 0.00 | -0.02 | 0.01 |
| South West | -0.01 | -0.02 | 0.01 |
| West Midlands | -0.01 | -0.03 | 0.00 |
| Yorkshire and The Humber | -0.02 | -0.03 | 0.00 |
Halving times in days, if a region shows growth than value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 64.90 | 41.37 | 158.59 |
| East of England | 27.85 | 16.57 | 94.78 |
| East Midlands | 26.62 | 15.58 | 85.97 |
| London | 105.13 | 30.22 | NA |
| North East | 38.72 | 18.02 | NA |
| North West | 27.34 | 14.88 | 110.01 |
| South East | 487.57 | 40.87 | NA |
| South West | 96.00 | 29.03 | NA |
| West Midlands | 69.84 | 25.15 | NA |
| Yorkshire and The Humber | 44.13 | 19.90 | NA |
Doubling times in days, if a region shows decline then the value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | NA | NA | NA |
| East of England | NA | NA | NA |
| East Midlands | NA | NA | NA |
| London | NA | 90.52 | NA |
| North East | NA | 422.26 | NA |
| North West | NA | NA | NA |
| South East | NA | 63.11 | NA |
| South West | NA | 124.22 | NA |
| West Midlands | NA | 174.94 | NA |
| Yorkshire and The Humber | NA | 2426.74 | NA |
NB: negative growth rates are rates of decline. Values are daily changes.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 0.00 | 0.00 | 0.01 |
| East of England | 0.00 | -0.01 | 0.01 |
| East Midlands | -0.01 | -0.02 | 0.01 |
| London | 0.00 | -0.01 | 0.02 |
| North East | 0.00 | -0.01 | 0.02 |
| North West | -0.01 | -0.02 | 0.00 |
| South East | 0.01 | 0.00 | 0.02 |
| South West | 0.01 | 0.00 | 0.03 |
| West Midlands | 0.01 | 0.00 | 0.02 |
| Yorkshire and The Humber | 0.00 | -0.01 | 0.01 |
Halving times in days, if a region shows growth than value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | NA | 1453.36 | NA |
| East of England | NA | 61.38 | NA |
| East Midlands | 82.98 | 34.65 | NA |
| London | NA | 106.40 | NA |
| North East | NA | 60.84 | NA |
| North West | 71.72 | 33.49 | NA |
| South East | NA | 206.64 | NA |
| South West | NA | NA | NA |
| West Midlands | NA | 156.22 | NA |
| Yorkshire and The Humber | NA | 64.26 | NA |
Doubling times in days, if a region shows decline then the value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 189.00 | 85.57 | NA |
| East of England | 2033.92 | 51.03 | NA |
| East Midlands | NA | 121.27 | NA |
| London | 157.00 | 41.93 | NA |
| North East | 287.66 | 39.57 | NA |
| North West | NA | 159.35 | NA |
| South East | 87.87 | 35.89 | NA |
| South West | 48.59 | 25.86 | 221.3 |
| West Midlands | 86.18 | 32.49 | NA |
| Yorkshire and The Humber | 639.77 | 46.76 | NA |
## The execution of the prevalence code block will proceed if
## prev.dat exists and this is TRUE
## it is not and external report and this is FALSEThe shaded areas show periods of national lockdown, the green lines the dates (once confirmed) of the steps in the roadmap in the UK Governement’s COVID-19 Response – Spring 2021, and the red line shows the date these results were produced (05 Nov).
The figure below shows the probability that \(R_t\) is greater than 1 (ie: the number of infections is growing) in each region over time. Clicking the regions in the legend allows lines to be added or removed from the figure.
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